MOTION SYSTEM TRENDS

for hazardous location ratings rule out most standard motor and drive solutions. “To serve engineers in this industry, we’ve released the world’s only ATEX-rated stepper drive for hazardous locations … and this year we’ll introduce our first explosion-proof step motor to pair with it,” said Eric Rice of Applied Motion Products. “The drive is already being used on rigs in the oil field for applications where accurate braking and speed control of drill strings are required.” MOTORS IN (PROLIFERATING) BATTERY-POWERED DESIGNS Battery-powered designs such as ATVs, mobile robotics (including AGVs), scooters, ebikes, and drones present unique motionsystem challenges. Motors that integrate into these designs might need to accept 48, 24, or 12-V input, and nearly all of them must meet tough efficiency requirements. “Battery-powered equipment is spurring more demand for high-efficiency dc motors,” said Paul McGrath, national sales manager at maxon precision motors. “Here, we supply motors for robots that navigate retail stores to check inventory and verify that items are placed on shelves in the proper locations — often during an end-of-the-day surveillance sweeps. Some of our motors get efficiencies to 90% — far better than the 60% for comparable motor offerings.” Ironless-core motors in particular eliminate the losses of iron components; coreless motors from the motor maker also avoid the stray losses of laminate cores. Permanent magnets in both brush and brushless offerings further support maximal efficiency. In some cases, software can predict motor-system efficiencies. One such application lets engineers check the performance of different motor technologies based on key parameters. “So an engineer may have different voltage options available for a battery-operated device and need to know the

efficiency of a motion solution at those different voltages,” said Dave Beckstoffer of Portescap. “Using MotionCompass software here, design engineers can quickly test different voltages to see changes in the design’s efficiency The DRS2 Series compact linear actuator (and power) — and from Oriental Motor is a precision get information that ballscrew actuator fitted with an AZ normally would’ve Series stepper motor and absolute required testing in a mechanical encoder. This is one example lab.” This shortens the of the industry trend towards increasingly engineering time and integrated stepper-motor designs. reduces iterations to get to a final design. Where mobile designs such as AGVs and utility-task vehicles use electric motors for embedded robotics, it’s often a frameless permanent-magnet motor that directly integrates into the wheel drive and runs off low voltage, according to Osak of Electromate. “In our marketplace, size requirements are increasingly challenging — with torque-density requirements also increasing … and that’s especially true for motion designs that run off lowvoltage battery-operated systems,” he added. Others agree. “Automated guided vehicles (AGVs) and other battery-powered equipment certainly require compactness. We see a trend towards higher-torque-density motors with integrated drive electronics as opposed to traditional BLDC motors with separate drives,” said Rice of Applied Motion Products. Rapid adoption of AGVs means a larger array of application requirements and a demand for faster design cycles. Here,

Portescap Ultra EC brushless dc motors have U-shaped coils to maximize power density — and let design engineers pick from multiple options to satisfy applications needing high speed, high torque, or both.

34

DESIGN WORLD — MOTION

Motors — Motion Control Trends 03.18 V3 FINAL.indd 34

3 • 2018

motioncontroltips.com | designworldonline.com

3/14/18 10:16 AM